VG00 Exporting to EMC

[Doug_85]

These are the tasks I'm trying to accomplish with the least amount of disturbance to the sytem and users.

1. Break mirror of 2 drives on L class
2. Move VG00 over to EMC (after mirror is broken)
3. Replace drive in L class with a larger drive and increase swap space from 512mb to 2GB.
4. Move VG00 back to L class server
5. Reestablish mirror.

System: HP-UX 11.0, L class server

Thanks,
Doug

[Sanjay_6 · Accepted solution]

Hi Doug,

Best solution is to do a ignite backup and do a ignite restore after replacing the internal disk with a bigger disk. Using an EMC disk will not help.

You'll run into the problem of adding a large disk to vg00. Something like the situation defined in the link below,

http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000063236226

The ITRC doc id is KBRC00001759.

Hope this helps.

Regds

[Sundar_7]

All that you are trying to accomplish is to increase the amount of swap space you have ? Why not add the larger drive as the additional swap space rather than complicating the things with so may moves and breaks.

[Doug_85]

The reason for so many breaks is that I need to get the OS which is on a 18GB drive (VG00) moved to a larger 36GB drive. Unfortunately, when the system was first setup the OS was placed on a smaller 18GB drive. We started replacing our older drives with the 36GB drives and are now down to the last 18GB drive that needs to be replaced.

Thanks,
Doug

[Sanjay_6]

Hi Doug,

Do a vgdisplay for VG00. Take a product of MAX_PE per PV and PE_Size. This will give you the maximum size of a disk that you can add as part of VG00 without recreating vg00.

To recreate vg00, the easy way out if you don't want to reload all the other S/W's is to take a ignite backup, Replace the disk and do a ignite restore.

Take a look at ignite site for more info on ignite.

http://www.software.hp.com/products/IUX/index.html

Hope this helps.

Regds

[Sundar_7]

OK now I understand. :-) . but unless otherwise somebody has foreseen this issue at the time of installing the OS, you are not going to have the MAX_PE and PE SIZE that can accommodate the 36GB drive.

The best way is to run a make_recovery (or make_tape_recovery), install the new drives and reinstall the OS from the recovery tape.

[Dave Wherry]

Doug,
All those 18Gb drives you replaced with 36GB drives, was the MAX_PE set to accomodate those larger drives?
When a volume group is created it automatically sets MAX_PE to match the largest drive being used at time of creation. That is then the maximum amount of a drive you can use.
You can add a 36GB drive later but, you will only be using 18GB of that drive unless you rebuild the volume group and set the MAX_PE.

If those volume groups did not have a large enough MAX_PE you are only using half of those 36GB drives.

[Doug_85]

Currently we are in the process of moving VG00 off of the 18GB drive then increasing the max PE size to accomadate the 36GB drive. This operation will not take place until this weekend when all users are off the system.

Thanks,
Doug